Electrical connector



Dec. 20, 1966 w, E, GROPP ETAL 3,293,355

ELECTRICAL CONNECTOR 2 Sheets-Sheet 1 INVENTORS.

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ELECTRICAL CONNECTOR Filed Feb. 6, 1964 2 Sheets-Sheet z WMMW HTTO/T/VEYS United States Patent O Pa., assignors to Berg Electronics, Inc., New Cumberland, Pa., a corporation of Pennsylvania Filed Feb. 6, 1964, Ser. No. 343,042 2 Claims. (Cl. 17484) This invention relates to electrical splice connections and to a method of and apparatus for making terminals for making such connections. The terminal or connector of our invention is particularly adapted for splicing one or more varnish-insulated solid magnet wires to one or more stranded leads. Splicing connectors known to the art are exemplified by US. Letters Patent, Nos. 1,646,660, 1,836,497, and 2,800,638.

A principal object of the present invention is to provide a new and improved connector for making splice connections and particularly one which is more satisfactory in operation and less expensive to produce.

Another object of the invention is to provide a new and improved splice connection.

Other and further objects of the invention will be apparent from the following description and claims and may be understood by reference to the accompanying drawings, of which there are two sheets, which by way of illustration show a preferred embodiment of the invention and what we now consider to be the best mode of applying the principles thereof. Other embodiments of the invention may be used without departing from the scope of the present invention as set forth in the appended claims.

In the drawings:

FIG. 1 is a side elevational view of a strip of connectors illustrating certain steps in the method of making a strip of connectors;

FIG. 2 is a plan view of the strip shown in FIG. 1;

FIG. 3 is an enlarged fragmentary sectional view of a connector taken along the line 33 of FIG. 1;

FIG. 4 is an enlarged cross sectional view of a connector taken along the line 44 of FIG. 1;

FIG. 5 is a somewhat schematic elevational view of tooling useful in forming ribs on the connector blank;

FIGS. 6 and 7 are views similar to FIG. 5, illustrating how the tooling operates to form the ribs on the surface of the connector blank;

FIG. 8 is a side elevational view of a splice connection between two electrical conductors made with the splice connector of this invention crimped on such conductors;

FIG. 9 is an enlarged cross sectional view of the crimped connector taken along the line 9-9 of FIG. 8;

FIG. 10 is an enlarged fragmentary sectional view taken along the line 1010 of FIG. 9; and

FIG. 11 is a fragmentary view illustrating the manner in which the ribs of the connector are embedded in the conductor metal during the crimping of the connector around the conductor.

As shown in FIGS. 1, 2, 3 and 4, a splice connector embodying our invention comprises a U-shaped metal ferrule 20 forming a channel 22, the surface of which is relieved by two series of like grooves 24 and 26 disposed transversely of the channel with the groove 24 of one series oriented oppositely relative to the groove 26 of the other series, and with the grooves 24 of one series spaced longitudinally of the channel from the grooves 26 of the other series. Each of the grooves 24 and 26 is asymmetrical in cross section. One side of each of the grooves 24 form a sharp-edged transverse rib or tooth 28 which projects above the inner surface 30 of the channel. Similarly, one side of each of the grooves 26 forms a sharpedged transverse rib or tooth 32 which projects above the inner surface of the channel and the opposite sides of the grooves 26. The ribs 28 of one series are inclined toward 3,293,355 Patented Dec. 20, 1966 ice the ribs 32 of the other series, and the spacing between adjacent grooves in each series is substantially greater than the width of each groove. Preferably the ribs or teeth 28 and 32 are formed with each having one surface 34 perpendicular to the longitudinal axis of the channel 22.

We have found it advantageous to make the connectors from strip stock which is subjected to a series of operations to form a plurality of blanks 40 serially connected by connecting strips 42, and which blanks are subjected to metal forming operations as hereinafter described to form the grooves 24 and 26 and the ribs 28 and 32, and then formed into U-shaped cross section to form a series of open ferrules 20. Preferably the sides 44 and 46 of the ferrules taper in height as shown in FIGS. 1 and 2 so as to increase in height in the direction of the inclination of the ribs 28 and 32. Thus the sides 44 and 46 are higher at the longitudinal center of the channel than at the ends.

In forming the grooves and ribs, the oppositely oriented sets of teeth of the punches 50 and 52 are forced against the surface and into the metal of the blank as illustrated in FIGS. 5, 6 and 7, with the cutting edges of the teeth 54 of one set facing away from the cutting edges of the teeth 56 of the other set while the punches 50 and 52 are moved laterally apart so that the teeth 54 and 56 move in their cutting direction to form the grooves 24 and 26 and to displace metal from the blank above the surface 30 thereof to form the two series of oppositely disposed ribs projecting above such surface 30.

In practice the blank is moved across a suitable supporting surface and a tool carrying the punches 50 and 52 is moved toward the surface 30 of the blank so as to bring the teeth 54 and 56 into contact therewith, the punches 50 and 52 being spring biased to their extended position and also biased by the springs 60 toward each other.

The tool holder 62 includes a tongue 64 which carries a cross pin 66 that projects into slots 68 in the punches 50 and 52. As the tool holder 62 and the punches 50 and 52 descend, the teeth 54 and 56 first contact the work and then continued movement of the tool holder 62 brings the wedge or cam surfaces 70 on the tongue 64 into engagement with the cam or wedge surfaces 72 on the punches 50 and 52, thereby first forcing the teeth 54 and 56 into the metal of the blank and then forcing the sets of teeth 54 and 56 apart while forcing the same further into the blank metal. The teeth 54 and 56 are thus simultaneously driven into the blank metal at an angle (that can be from 10 to to simultaneously produce the grooves 24 and 26 and the ribs 28 and 32. The number of ribs and the spacing between the adjacent ribs of each set are not critical, and while we prefer that the edges of the ribs be sharp, they may be provided with a relatively small land area if desired.

The electrical conductors to be spliced are positioned in the channel 22 in overlapping relation and the open ferrule is then crimped around the wires under metal-deforming pressure so as to integrate the same into a unitary mass as shown in FIG. 9 whereby extrusions 81 of the conductor metal fill the cavities provided by the grooves 24 and 26 and the ribs 28 and 32 are embedded in the conductor metal. Where the conductors 80 are varnished or otherwise insulated as indicated at 82, the teeth or ribs 28 will pierce the insulation so that the conductor metal may be brought into intimate metal-to-metal engagement with the metal of the connector as illustrated in FIG. 10. When the sides 44 and 46 of the connectors have tapered upper edges as shown in FIGS. 1 and 2, a higher crimping force will be created in the center of the connector than at the ends, causing extrusion or metal flow of the conductor metal. Since the connector material is harder than the conductor material, the latter will flow more readily, providing a good metal-to-metal contact along the surface 34 of each rib. The crimping operation may be 3 carried out with crimping dies of the type generally illustrated in Berg Patent No. 3,020,520.v

We have obtained excellent results using three-quarter hard brass strip stock for the connectors of .018 inch nominal thickness.

While we have illustrated and described a preferred embodiment of our invention, it is understood that this is capable of modification, and we therefore do not wish to be limited to the precise details set forth but desire to avail ourselves of such changes and alterations as fall within the purview of the following laims.

We claim:

1. An electrical connector adapted for crimping around one or more conductors, said connector comprising a ferrule forming channel having two series of flat topped inclined ribs formed on the inside of the channel and extending transversely of the channel with the ribs of one series inclined toward the ribs of the other series and with one series spaced longitudinally of the channel so as to be disposed at one end of the other series, a flat topped central rib separating said series of ribs, the tops of all of said ribs defining the inner surface of said channel, the sides of adjacent ribs intersecting at an acute angle to form V-shaped grooves between such ribs with the grooves adjacent one series of ribs inclined toward the ribs of the other series, the one side of each rib in each series facing the other series being oriented perpendicular to said surface and extending upwardly past said surface to form a sharp cutting edge above the top of such rib, the other side of each rib in each series and both sides of said central rib being oriented obliquely to said surface so as to make an obtuse angle therewith, the width of said ribs being substantially greater than the width of said grooves.

2. A connector according to claim 1 wherein said channel comprises a U-shaped sheet metal blank, the sides of which taper so as to increase in height in the direction of the inclination of said ribs whereby upon crimping of said connector said sides are brought into abutment and create a higher crimping force adjacent said central rib than to either side thereof to cause extrusion of the conductors away from said central rib and past said series of ribs so as to establish a positive electrical connection between 0 said connector and the conductors.

References Cited by the Examiner UNITED STATES PATENTS 2,436,111 2/1948 Lowe 83-9 2,677,313 5/1954 Biegert 835 2,799,721 7/1957 Floyd 17484 X 3,015,683 1/1962 OKeefe et al. 174-84 3,036,147 5/1962 Wheatton et al 174-84 3,048,650 8/ 1962 Allen et al. 17490 3,111,554 11/1963 Harris 17484 LEWIS H. MYERS, Primary Examiner.

DARRELL L. CLAY, Examiner. 

1. AN ELECTRICAL CONNECTOR ADAPTED FOR CRIMPING AROUND ONE OR MRE CONDUCTORS, SAID CONNECTOR COMPRISING A FERRULE FORMING CHANNEL HAVING TWO SERIES OF FLAT TOPPED INCLINED RIBS FORMED ON THE INSIDE OF THE CHANNEL AND EXTENDING TRANSVERSELY OF THE CHANNEL WITH THE RIBS OF ONE SERIES INCLINED TOWARD THE RIBS OF THE OTHER SERIES AND WITH ONE SERIES SPACED LONGITUDINALLY OF THE CHANNEL SO AS TO BE DISPOSED AT ONE END OF THE OTHER SERIES, A FLAT TOPPED CENTRAL RIB SEPARATING SAID SERIES OF RIBS, THE TOPS OF ALL OF SAID RIBS DEFINING THE INNER SURFACE OF SAID CHANNEL, THE SIDES OF ADJACENT RIBS INTERSECTING AT AN ACUTE ANGLE TO FORM V-SHAPED GROOVES BETWEEN SUCH RIBS WITH THE GROOVES ADJACENT ONE SERIES OF RIBS INCLINED TOWARD THE RIBS OF THE OTHER SERIES, THE ONE SIDE OF EACH RIB IN EACH SERIES FACING THE OTHER SERIES BEING ORIENTED PERPENDICULAR TO SAID SURFACE AND EXTENDING UPWARDLY PAST SAID SURFACE TO FORM A SHARP CUTTING EDGE ABOVE THE TOP OF SUCH RIB, THE OTHER SIDE OF EACH RIB IN EACH SERIES AND BOTH SIDES OF SAID CENTRAL RIB BEING ORIENTED OBLIQUELY TO SAID SURFACE SO AS TO MAKE AN OBTUSE ANGLE THEREWITH, THE WIDTH OF SAID RIBS BEING SUBSTANTIALLY GREATER THAN THE WIDTH OF SAID GROOVES. 